Growing Leeks: From Planting to Harvest

About Leeks

Milder, sweeter, and more digestible than onions/garlic. Keep well in ground; harvest year-round in mild climates.

Upon Receipt

Live plants (not sets). Plant ASAP. If delayed, spread in cool, dry area; they survive 2–3 weeks on stored energy.

Soil Preparation

Fertile, well-drained, balanced nutrients. Organic: rich compost. Lime if pH <6.0. Commercial: 10-20-10 at ½ cup per 10 linear feet, worked into top 4–6 inches.

Planting Methods

Hole method: Poke 6–8″ holes with hoe handle, set plants so youngest leaves just show. Water in to settle soil and blanch stems. Trench method: Dig 8″ trench, set leeks 6″ apart, fill and firm.

Blanching

Deep planting blanches stems (white, tender, flavorful). Mound soil around stems every 2 weeks until full height.

Fertilizing

High nitrogen needed. Liquid fish emulsion or similar 3 weeks after planting; repeat every 3–4 weeks. Water in dry granular fertilizer.

Watering

Keep soil evenly moist. Dryness causes uneven growth, strong flavor, pithy texture.

Weed Control

Hand-weed/hoe early. Don't damage young plants. Keep soil loose, mound dirt to blanch. Light organic mulch helps.

Diseases & Insects

Generally trouble-free. Blight (pale-green then yellow leaves) and purple blotch (purple lesions) favored by dew/fog/rain. Prevention: well-drained soil, rows parallel to prevailing winds, avoid windbreaks. Fungicide if needed. Onion thrips (light brown, <1/16″) cause silvery blotches. Reduce weeds; treat with insecticidal soap or pyrethrin.

Harvest & Storage

Early variety (~70 days). Can harvest anytime as scallion substitute. No rest period needed. Best fresh; stores up to a week in fridge if kept moist. Loosen with fork, pull, shake dirt. For storage, cut tops in V-shape to reduce withering.